1. Field of the Invention
This invention relates to a method and system for generating power. This invention relates to a method and system for generating power using gas turbines. This invention relates to a method and system for generating power using partial oxidation gas turbines. This invention relates to a method and system for generating power employing non-conventional cooling fluids for cooling the components of the power generation system.
2. Description of Related Art
In order to increase thermal efficiency, modern gas turbines operate at increased working temperatures which could be as high as 2700° F., and gas turbine manufacturers are working on designs capable of operating at turbine inlet temperatures up to about 3000° F. Conventional turbine cooling is accomplished through the use of internally cooled turbine blade and vane construction wherein a cooling fluid is circulated through the internal flow passages of the turbine components. See, for example, U.S. Pat. No. 5,279,111 Application of gas turbine cooling allows gas turbines to operate at temperatures exceeding normal material temperature limits. In conventional gas turbines, air from the compressor or externally generated steam is employed for turbine component cooling so as to maintain the metal temperatures within their design limits, usually in the range of 1500° F. to 1700° F., depending upon the alloys used to manufacture the turbine components.
In a partial oxidation gas turbine (POGT), the conventional combustor of a gas turbine is replaced with a non-catalytic partial oxidation reactor (POR) in which natural gas or another fuel is combusted with compressed air at substoichiometric conditions. Typically fueled by natural gas, the partial oxidation gas turbine can provide high-efficiency electricity generation from expansion of the hot, pressurized partial oxidation products through the gas turbine, while producing an exhaust consisting of a high-temperature fuel gas, such as a hydrogen-rich fuel gas. This clean, hydrogen-rich fuel gas is suitable for use in fuel cells, existing fossil fuel-fired furnaces, boilers, conventional gas turbine engines, and for hydrogen and syngas production. However, in contrast with conventional gas turbines, direct air cooling of partial oxidation gas turbine components is problematic because the working fluid is a hot, combustible fuel gas. As a result, the only remaining conventional cooling option available is the utilization of steam as a cooling fluid. However, the utilization of steam cooling reduces the thermal efficiency of the partial oxidation gas turbine system.